Gluten-free sports diets do nothing, study suggests

In healthy, non-celiac athletes, gluten made no difference in digestion or workouts.

Ditching the notorious complex of proteins known as gluten is a popular diet plan nowadays. Besides people with celiac disease, a severe autoimmune disorder triggered by the proteins, athletes have been particularly smitten with the gluten-free fad. But, according to a recent study, the diet is unlikely to give them the results they expect.

She and her colleagues got the idea to test the effects in athletes after previous studies had reported that gluten-free diets had taken off in the sports world. Many athletes reported thinking that skipping gluten, which is found in wheat and other grains, could improve their digestive health—a common problem for athletes.

As many as 90 percent of long-distance runners, cyclists, and high-endurance athletes complain of gastrointestinal problems, such as cramps and diarrhea. The problems may, in part, arise as blood and fluid get diverted from the gut during exercise to hard-working body parts like arms and legs.

To test whether going gluten-free would tame those troubled tummies, Lis and colleagues cooked up two versions of a sports bar. The two bars tasted exactly the same, but one was gluten-free and the other a gluten bomb.

In a two-week study, 13 cyclists were told to eat gluten-free on their own and were given the bars during monitored workouts—a week of gluten bars and a week of gluten-free bars. But, neither the researchers nor the athletes knew which type of bar each cyclist was eating each week.

Though the study was small and short-term, Lis says the clear takeaway is that gluten-free diets are not a cure-all. “I hope that people learn to be more objective in terms of what they hear and read about gluten-free diets and nutrition in general,” she said.